African Fusion March 2015

Cover Story: Lincoln Electric

Total solutions for tank fabrication For the welding of large storage tanks, a partnership between local automation specialist Mazolutions, Lin- coln Electric and Chinese-based All Time is dramatically improving the quality and productivity of storage tank construction for the oil and gas sector. African Fusion talks to Andrew Masuret, MD of Mazolutions, about the technology.

Andrew Masuret, MD of Mazolutions.

M azolutions’ partnership with Lincoln Electric began with a project in Secunda to refurbish ashlock vessels, which are part of the coal gasification process. “We represent an agency out of Germany called Kistler Machines, an automation specialist that engineers and supplies a range of manipulators and cutting machines. With Kistler as our manipulation part- ner and Lincoln on the welding side, we were able to develop a highly successful system to do weld overlay cladding on ashlock vessels. “We landed an order in 2008 for a system to deposit an erosion and cor-

rosion protective layer to extend the life of the ash collection and removal system on these complex-shaped ves- sels. We remove about 15 mm of exist- ing material from the worn vessels and then build the whole surface back up to OEM specifications,” Masuret explains, adding, “this has been an amazingly successful application”. “In Europe, Kistler is also very strong on onshore and offshore wind tower fabrication solutions, which is becom- ing increasingly interesting to us here in South Africa,” he adds. “Kistler wind tower systems offer significant pro- ductivity advantages, because they are fabricated using multi-wire submerged arc welding systems and two circumferential seams can be welded simultaneously, so eight wires can be deposited into two seams at the same time,” Masuret reveals. “We have exceled in weld overlay type applications, and we are currently looking at twin-wire hot-wire TIG applications, which are commonly used in the oil and gas industry,” he says. Moving on to another core spe- cialism, the welding of tank seams for large fuel andgas storage vessels, Masuret tells of his partnership with Chinese based All Time. “All Time specialise in welding the vertical and circumferential seams for large storage tanks with diameters of anywhere between 6.0mand 100m. All Time is one of Lincoln Electric’s biggest distributors in Asia, but the owner, Ricky Leung, realised that supplying product was not enough, so he began to put together turnkey solutions for the tank fabrication

business,” Masuret tells African Fusion . All Time’s systems for tank farm fab- rication are built around Lincoln equip- ment and consumables for two welding processes; submerged-arc automatic girthwelding (AGW) for the circumferen- tial seams and self-shielded electro-gas welding (EGW) for the vertical seams. Describing how these storage tanks are built, Masuret says that there are two basic construction techniques: the conventional from the floor up tech- nique; and jack up systems that are built from the roof down. “With the jack up system, the roof is fabricated first, then the whole structure is jacked up and the panel sections are welded in underneath. All Timemakes equipment suitable for both techniques. Its jack up system allows a tank to be jacked up to accommodate the next section within about 15 minutes. This is amazing to see. A 28 m high structure with a 100 m diameter is lifted by 1.5 to 3.0 m to ac- commodate the next level, all using a synchronised set of hydraulic jacks around the periphery,” he relates. The floor-up technique is more commonly used in Africa. Pre-rolled plate sections with accurately cut weld preparations are lifted, one by one, onto locating supports and tacked into place. The vertical seams between each plate section are then completed. “Traditionally, SMA (stick) welding was used to complete these joints, and it would take a manual welder about two days to fill a single 2,4 m joint. We experimented with various types of equipment, for a period of time, trying to find a solution for the vertical joints. But modern All Time systems use the EGW process, which is almost like a

All Time’s systems for tank farm fabrication are built around Lincoln equipment and consumables for two welding processes; submerged-arc automatic girth welding (AGW) for the circumferential seams and self-shielded electro-gas welding (EGW) for the vertical seams.

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March 2015

AFRICAN FUSION